"LWE (left wing extremism) groups have been trying to establish links abroad through other Indian separatist or insurgent groups, particularly in the North-East, and foreign intelligence agencies and arms dealers have been trying to contact the LWE groups as well", he said.

India is also seeing a marked rise in communally inflammatory materials posted on the net, some of it maliciously manipulated and designed to inflame passions and provoke violence, Menon said delivering the Dr. Raja Ramanna lecture on India's external and internal security at the National Institute of Advanced Studies here.

"These tools are being used to mobilise ethnic and religious groups, to incite communal violence and to destabilise social order", he said.

"While much of the malicious incitement came from within the country, the material used, the technologies, sites, and services involved and some of the incitement came from outside India", he added.

He also pointed to turmoil in West Asia, North Africa and the Gulf from where India gets over 60 per cent of its oil imports, adding the Muslim Ummah is getting increasingly disturbed and politically radicalised from Morocco to Indonesia through Malaysia, Myanmar, India, Pakistan, the Gulf, the Levant and North Africa.

"Our energy security is under pressure", Menon said. He said the "disturbed state" of the Ummah should make India even more sensitive to the dangers of communal incitement.

"We have had an enviable record of communal harmony in India over the last eight years. However, there are worrying signs in 2012. Communal violence levels have risen", Menon said.

"While we have improved our capabilities and performance in several internal security tasks, external factors and influences are likely to make our life in India harder in the immediate future", he added.